Estimating Distance from Parallaxes (gdr2_contrib.starhorse)

Description

Estimating Distance from Parallaxes. IV. Distances to 1.33 Billion Stars in Gaia Data Release 2. For the vast majority of stars in the second Gaia data release, reliable distances cannot be obtained by inverting the parallax. A correct inference procedure must instead be used to account for the nonlinearity of the transformation and the asymmetry of the resulting probability distribution. Here, we infer distances to essentially all 1.33 billion stars with parallaxes published in the second Gaia data release. This is done using a weak distance prior that varies smoothly as a function of Galactic longitude and latitude according to a Galaxy model. The irreducible uncertainty in the distance estimate is characterized by the lower and upper bounds of an asymmetric confidence interval. Although more precise distances can be estimated for a subset of the stars using additional data (such as photometry), our goal is to provide purely geometric distance estimates, independent of assumptions about the physical properties of, or interstellar extinction toward, individual stars. We analyze the characteristics of the catalog and validate it using clusters.

Columns

Name Type UCD Unit Description
source_id long meta.id Unique source identifier (unique within a particular Data Release)
sh_photoflag char StarHorse photometry input flag
sh_parallaxflag char StarHorse parallax input flag
sh_gaiaflag char StarHorse GDR2 quality flag
sh_outflag char StarHorse output quality flag
dist05 double pos.distance StarHorse distance, 5th percentile
dist16 double pos.distance StarHorse distance, 16th percentile
dist50 double pos.distance StarHorse distance, 50th percentile
dist84 double pos.distance StarHorse distance, 84th percentile
dist95 double pos.distance StarHorse distance, 95th percentile
av05 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction at 5420 nm, A_V, 5th percentile
av16 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction at 5420 nm, A_V, 16th percentile
av50 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction at 5420 nm, A_V, 50th percentile
av84 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction at 5420 nm, A_V, 84th percentile
av95 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction at 5420 nm, A_V, 95th percentile
ag50 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction in the Gaia DR2 G band (Maiz-Apellaniz & Weiler 2018), A_G, 50th percentile
teff16 double phys.temperature.effective Temperature[K] StarHorse effective temperature, 16th percentile
teff50 double phys.temperature.effective Temperature[K] StarHorse effective temperature, 50th percentile
teff84 double phys.temperature.effective Temperature[K] StarHorse effective temperature, 84th percentile
logg16 double phys.gravity cgs[dex] StarHorse surface gravity, 16th percentile
logg50 double phys.gravity StarHorse surface gravity, 50th percentile
logg84 double phys.gravity cgs[dex] StarHorse surface gravity, 84th percentile
met16 double phys.abund.Z cgs[dex] StarHorse metallicity, 16th percentile
met50 double phys.abund.Z cgs[dex] StarHorse metallicity, 50th percentile
met84 double phys.abund.Z cgs[dex] StarHorse metallicity, 84th percentile
mass16 double phys.mass Mass[solar] StarHorse stellar mass, 16th percentile
mass50 double phys.mass Mass[solar] StarHorse stellar mass, 50th percentile
mass84 double phys.mass Mass[solar] StarHorse stellar mass, 84th percentile
abp50 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction in the G_BP band (Maiz-Apellaniz & Weiler 2018), A_BP, 50th percentile
arp50 double phys.absorption.gal Magnitude[mag] StarHorse line-of-sight extinction in the G_RP band (Maiz-Apellaniz & Weiler 2018), A_RP, 50th percentile
bprp0 double Magnitude[mag] StarHorse dereddened G_BP - G_RP colour, derived from phot_bp_mean_mag, phot_rp_mean_mag, Teff50 and AV50
mg0 double Magnitude[mag] StarHorse absolute magnitude, derived from phot_g_mean_mag_oct2018, dist50, and AG50
xgal double pos.distance kpc StarHorse Galactocentric Cartesian X coordinate, derived from dist50
ygal double pos.distance kpc StarHorse Galactocentric Cartesian Y coordinate, derived from dist50
zgal double pos.distance kpc StarHorse Galactocentric Cartesian Z coordinate, derived from dist50
rgal double pos.distance kpc StarHorse Galactocentric distance, derived from dist50 and assuming R_0 = 8.33 kpc
ruwe double Gaia DR2 renormalised unit weight error (RUWE; Lindegren 2018)